Alterations in laryngeal mechanics have been shown in patients with chronic obstructive pulmonary disease (COPD), but the relationships between respiration, altered laryngeal mechanics, and aspiration have not been studied. Though airway closure mechanisms have been defined in healthy adults, and swallowing changes associated with normal aging have been described, there has not been study of the temporal coordination between respiration and laryngeal dynamics in groups of young and healthy adults. This work is necessary prior to studies of these relationships and their potential contribution to chronic pulmonary disease. This novel, nasal airflow recording study, using dual modality videofluoroscopy, is designed to define the transitioning of laryngeal dynamics between respiration and swallowing activity in groups of healthy young and aging adult humans. Specific aims include: 1) defining the temporal order and durations of respiratory related events and hyolaryngeal dynamics during liquid swallowing in healthy adults; 2) determining the impact of age on temporal clusters of physiologic respiratory and hyolaryngeal swallowing dynamics, and 3) identifying the influence of age on swallowing patterns during sequential swallowing. Respiratory flow and laryngeal dynamic measures will be obtained for single bolus and sequential liquid swallows. This study will emphasize the estimation of descriptive statistics as a precursor to a larger, population-level study. Cluster analysis will be applied to identify critical clusters of respiratory-swallowing dynamics. Mixed- effects analysis of variance will estimate the key study parameters of age group specific durations and variability.